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Nicholas D Sidiropoulos - One of the best experts on this subject based on the ideXlab platform.

  • fast algorithms for joint multicast beamforming and Antenna Selection in massive mimo
    IEEE Transactions on Signal Processing, 2020
    Co-Authors: Mohamed Salah Ibrahim, Aritra Konar, Nicholas D Sidiropoulos
    Abstract:

    Massive MIMO is currently a leading physical layer technology candidate that can dramatically enhance throughput in 5G systems, for both unicast and multicast transmission modalities. As Antenna elements are becoming smaller and cheaper in the mmW range compared to radio frequency (RF) chains, it is crucial to perform Antenna Selection at the transmitter, such that the available RF chains are switched to an appropriate subset of Antennas. This paper considers the joint problem of multicast beamforming and Antenna Selection for a single multicast group in massive MIMO systems. The prior state-of-art for this problem relies on semi-definite relaxation (SDR), which cannot scale up to the massive MIMO regime. A successive convex approximation (SCA) based approach is proposed to tackle max-min fair joint multicast beamforming and Antenna Selection. The key idea of SCA is to successively approximate the non-convex problem by a class of non-smooth, convex optimization problems. Two fast and memory efficient first-order methods are proposed to solve each SCA subproblem. Simulations demonstrate that the proposed algorithms outperform the existing state-of-art approach in terms of solution quality and run time, in both traditional and especially in massive MIMO settings.

  • joint multicast beamforming and Antenna Selection
    IEEE Transactions on Signal Processing, 2013
    Co-Authors: Omar Mehanna, Nicholas D Sidiropoulos, Georgios B Giannakis
    Abstract:

    Multicast beamforming exploits subscriber channel state information at the base station to steer the transmission power towards the subscribers, while minimizing interference to other users and systems. Such functionality has been provisioned in the long-term evolution (LTE) enhanced multimedia broadcast multicast service (EMBMS). As Antennas become smaller and cheaper relative to up-conversion chains, transmit Antenna Selection at the base station becomes increasingly appealing in this context. This paper addresses the problem of joint multicast beamforming and Antenna Selection for multiple co-channel multicast groups. Whereas this problem (and even plain multicast beamforming) is NP-hard, it is shown that the mixed l1,∞-norm squared is a prudent group-sparsity inducing convex regularization, in that it naturally yields a suitable semidefinite relaxation, which is further shown to be the Lagrange bi-dual of the original NP-hard problem. Careful simulations indicate that the proposed algorithm significantly reduces the number of Antennas required to meet prescribed service levels, at relatively small excess transmission power. Furthermore, its performance is close to that attained by exhaustive search, at far lower complexity. Extensions to max-min-fair, robust, and capacity-achieving designs are also considered.

Ali Ghrayeb - One of the best experts on this subject based on the ideXlab platform.

  • On the diversity order of space-time trellis codes with receive Antenna Selection over fast fading channels
    IEEE Transactions on Wireless Communications, 2006
    Co-Authors: A. Sanei, Ali Ghrayeb, Yousef R. Shayan, Tolga M Duman
    Abstract:

    In this paper, we study the performance of space-time trellis codes (STTCs) with receive Antenna Selection over fast fading channels. Specifically, we derive upper bounds on the pairwise-error probability (PEP) with Antenna Selection. In performing the Selection, we adopt a criterion that is based on using L out of the available M receive Antennas that result in maximizing the instantaneous signal-to-noise ratio (SNR) at the receiver, where L les M. We show that the diversity order resulting from Antenna Selection deteriorates significantly and is actually dictated by the number of selected Antennas. The implication of this result is that adding more receive Antennas, while maintaining the same number of selected ones, will have no impact on the diversity order, but it does, however, provide some additional coding gain. This is unlike the case for quasi-static fading channels in which the diversity order is always preserved with Antenna Selection when the underlying STTC is full-rank. We present numerical examples that support our analysis

  • Analysis of the outage probability for MIMO systems with receive Antenna Selection
    IEEE Transactions on Vehicular Technology, 2006
    Co-Authors: Hao Shen, Ali Ghrayeb
    Abstract:

    This paper presents a comprehensive analysis of the outage probability for multiple-input-multiple-output (MIMO) systems with receive Antenna Selection. In this analysis, it is assumed that 1) for a given M receive Antennas, the receiver selects the best L Antennas that maximize the capacity, 2) the channel state information is perfectly known at the receiver, but not at the transmitter, 3) the subchannels fade independently, and 4) the fading coefficients change very slowly such that averaging with respect to these coefficients is not possible. Under these assumptions, two upper bounds on the outage probability with receive Antenna Selection are derived. The first bound is used to show that the diversity order is maintained with Antenna Selection. The second bound is used to approximate the degradation in signal-to-noise ratio due to Antenna Selection. Furthermore, the asymptotic behavior of the outage probability for MIMO systems is analyzed as the number of transmit Antennas tends to infinity. The asymptotic results presented are extended to the case with receive Antenna Selection. For all cases, explicit expressions for the threshold for the outage probability are derived. Several numerical examples that validate the analysis are also presented

  • analysis of the outage probability for spatially correlated mimo channels with receive Antenna Selection
    Global Communications Conference, 2005
    Co-Authors: Hao Shen, Ali Ghrayeb
    Abstract:

    In this paper, we present a comprehensive analysis of the outage probability for multiple-input multiple-output (MIMO) systems with receive Antenna Selection over spatially correlated fading channels. In our analysis, we assume that 1) the channel state information (CSI) is perfectly known at the receiver but not at the transmitter, 2) Antenna Selection is based on maximizing the channel capacity, 3) the spatial correlation is present at both ends of the wireless communications link, 4) the transmit and receive correlation matrices may or may not be full rank, and 5) the underlying channel is quasi-static fading. With these assumptions, we derive explicit bounds for the outage probability and show that the diversity order is the same as that of the full complexity system. We also derive an expression that quantifies the loss in signal-to-noise ratio (SNR) due to Antenna Selection We also present several numerical examples that validate our analysis

Tolga M Duman - One of the best experts on this subject based on the ideXlab platform.

  • performance analysis of transmit and receive Antenna Selection over flat fading channels
    IEEE Transactions on Wireless Communications, 2008
    Co-Authors: Tansal Gucluoglu, Tolga M Duman
    Abstract:

    The paper considers two different Antenna Selection schemes for space-time coded systems over flat fading channels. First we explore Antenna Selection at the transmitter side based on the received signal to noise ratios. We then study the joint Selection of receive and transmit Antennas. Both schemes assume a slowly fading channel (i.e., quasi-static fading) and require some limited feedback from the receiver to the transmitter. By computing upper bounds on the pairwise error probabilities and conducting extensive simulations, we show that the space-time coded systems achieve full diversity even with Antenna Selection provided that the code is full rank. These results are extensions of earlier work on Antenna Selection for MIMO systems (Bahceci et al., 2003) which only considers receive Antenna Selection.

  • On the diversity order of space-time trellis codes with receive Antenna Selection over fast fading channels
    IEEE Transactions on Wireless Communications, 2006
    Co-Authors: A. Sanei, Ali Ghrayeb, Yousef R. Shayan, Tolga M Duman
    Abstract:

    In this paper, we study the performance of space-time trellis codes (STTCs) with receive Antenna Selection over fast fading channels. Specifically, we derive upper bounds on the pairwise-error probability (PEP) with Antenna Selection. In performing the Selection, we adopt a criterion that is based on using L out of the available M receive Antennas that result in maximizing the instantaneous signal-to-noise ratio (SNR) at the receiver, where L les M. We show that the diversity order resulting from Antenna Selection deteriorates significantly and is actually dictated by the number of selected Antennas. The implication of this result is that adding more receive Antennas, while maintaining the same number of selected ones, will have no impact on the diversity order, but it does, however, provide some additional coding gain. This is unlike the case for quasi-static fading channels in which the diversity order is always preserved with Antenna Selection when the underlying STTC is full-rank. We present numerical examples that support our analysis

  • Antenna Selection for multiple Antenna transmission systems performance analysis and code construction
    International Symposium on Information Theory, 2003
    Co-Authors: Israfil Bahceci, Tolga M Duman, Y Altunbasak
    Abstract:

    This correspondence studies Antenna Selection for wireless communications systems that employ multiple transmit and receive Antennas. We assume that (1) the channel is characterized by quasi-static Rayleigh flat fading, and the subchannels fade independently, (2) the channel state information (CSI) is exactly known at the receiver, (3) the Selection is available only at the receiver, and it is based on the instantaneous signal-to-noise ratio (SNR) at each receive Antenna, and (4) space-time codes are used at the transmitter. We analyze the performance of such systems by deriving explicit upper bounds on the pairwise error probability (PEP). This performance analysis shows that (1) by selecting the set of Antennas that observe the largest instantaneous SNR, one can achieve the same diversity gain as the one obtained by using all the receive Antennas, provided that the underlying space-time code has full spatial diversity, and (2) in the case of rank-deficient space-time codes, the diversity gain may be dramatically reduced when Antenna Selection is used. However, we emphasize that in both cases the coding gain is reduced with Antenna Selection compared to the full complexity system. Based on the upper bounds derived, we describe code design principles suitable for Antenna Selection. Specifically, for systems with two transmit Antennas, we design space-time codes that perform better than the known ones when Antenna Selection is employed. Finally, we present numerical examples and simulation results that validate our analysis and code design principles.

Alan Gatherer - One of the best experts on this subject based on the ideXlab platform.

  • Antenna Selection for large scale mimo systems with low resolution adcs
    International Conference on Acoustics Speech and Signal Processing, 2018
    Co-Authors: Jinseok Chai, Junmo Sung, B L Evans, Alan Gatherer
    Abstract:

    One way to reduce the power consumption in large-scale multiple-input multiple-output (MIMO) systems is to employ low-resolution analog-to-digital converters (ADCs). In this paper, we investigate Antenna Selection for large-scale MIMO receivers with low-resolution ADCs, thereby providing more flexibility in resolution and number of ADCs. To incorporate quantization effects, we generalize an existing objective function for a greedy capacity-maximization Antenna Selection approach. The derived objective function offers an opportunity to select an Antenna with the best tradeoff between the additional channel gain and increase in quantization error. Using the generalized objective function, we propose an Antenna Selection algorithm based on a conventional Antenna Selection algorithm without an increase in overall complexity. Simulation results show that the proposed algorithm outperforms the conventional algorithm in achievable capacity for the same number of Antennas.

Le Chung Tran - One of the best experts on this subject based on the ideXlab platform.

  • Antenna Selection strategies for mimo ofdm wireless systems an energy efficiency perspective
    IEEE Transactions on Vehicular Technology, 2016
    Co-Authors: Ngoc Phuc Le, Farzad Safaei, Le Chung Tran
    Abstract:

    In this paper, we investigate Antenna Selection strategies for multiple-input–multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) wireless systems from an energy efficiency (EE) perspective. We first derive closed-form expressions of the EE and the energy efficiency–spectral efficiency (EE–SE) tradeoff in conventional Antenna Selection MIMO-OFDM systems. The obtained results show that these systems suffer from a significant loss in EE. To achieve a better EE performance, we propose an adaptive Antenna Selection method where both the number of active radio-frequency chains and the Antenna indexes are selected depending on the channel condition. This Selection scheme could be implemented by an exhaustive search technique for a small number of Antennas. Moreover, we develop a greedy algorithm that achieves a near-optimal performance with much lower complexity compared with the (optimal) exhaustive search method when the number of Antennas is large. In addition, the efficacy of power loading across subcarriers for improved EE in the conventional and proposed Antenna Selection MIMO-OFDM systems is considered. Monte Carlo simulation results are provided to validate our analyses.